BERLIN — It’s been a little over a month since German driving legend Michael Schumacher suffered severe trauma to his skull and brain in a ski accident on the slopes above Méribel, France. He has been in an artificially induced coma since then, though news came Thursday that doctors have finally begun the slow “waking up” process.

“We pray, we wish, we hope that a miracle comes to pass and the man who wakes up from the coma is the same man he was before the accident,” star driver Sebastian Vettel says.

But the healing process after such severe accidents depends on many different factors, and is unique to each individual. Outcomes are difficult even for attending physicians to predict.

Many others share the same fate as Schumacher, who is being treated at a hospital in Grenoble, France. In Germany alone, some 248,000 people a year suffer cranial trauma, and it is the major cause of death among those under 45.

In severe cases like Schumacher’s, intensive care specialists agree that an artificially induced coma is the best course of action. After such a violent fall, the brain swells the way any other body part would. And yet there isn’t room inside the skull for swelling, which traps blood vessels and endangers oxygen supply. Deprived of oxygen, more and more nerve cells die, and the risk of permanent damage increases.

Artificially induced coma — basically long-term narcosis — reduces the oxygen needs of nerve cells and hence reduces swelling. It also stabilizes circulation and prevents the patient from experiencing heavy levels of pain or anxiety that would keep the body in a permanent state of stress.

A rule of thumb among doctors is that induced comas should be maintained for as long as necessary, but no longer, so that the patient’s control over his body is restored quickly. “Medically, the goal is always to end artificially induced comas as soon as possible,” says Andreas Zieger of the Department of Special Needs Education and Rehabilitation at Oldenburg University. “It will only be kept up if there are major reasons to do so — for example, because the brain urgently requires support in order to heal.”

According to Zieger, a neurosurgeon, the longer a coma lasts the more severe the underlying reason for it — or the possibility of later complications arising. “The complication rate rises every day the patient spends in such a coma — which means the prognosis for the patient becomes less and less good,” he says. Some 40% to 50% of patients with severe head trauma in an artificially induced coma die in intensive care.

The other half of patients make it through, but many have to deal with considerable complications. “How damaged the brain is depends on what tissue was destroyed and to what extent,” says Claudia Spies, head of the anesthesiology clinic specializing in operative intensive medicine at Berlin’s Charité Hospital. “If, for example, there was a lot of bleeding on the right side of the brain, then you can count on decrease of function in the left-hand side of the body.”

Damage can’t be predicted

Doctors cannot, however, predict with any precision to what extent there will be bodily or cognitive damage, not least because swollen tissue may regenerate. Frequent consequences of severe head trauma are motor and speaking difficulties, but memory, concentration, and the speed of thought may also be affected. There are also often personality changes: Patients may become more aggressive, depressive, or experience mood swings.

Narcosis also has side effects, as do long periods spent lying in bed and artificial respiration, which can lead to thrombosis or infections like inflammation of the lungs. Long term, the immune system may be weakened, and there can be blood pressure, nerve and muscle issues, or long-lasting disturbances of consciousness and perception.

To avoid or at least minimize such effects, doctors try to mobilize and stabilize patients early on, Zieger says. “But the extent to which that is possible depends on the patient’s reactions.”

If the patient is in a relatively deep artificial coma, mobility will be limited to moving their arms and legs, or making fists with their hands. Later, the patient can be raised to a vertical position in bed. This has a positive effect on alertness, Zieger says. In cases of severe trauma, as soon as bleeding and swelling have substantially subsided, narcosis is reduced little by little and doctors work towards getting the patient to regain control of his body. Slowly the patient regains consciousness.

“In severe cases, waking comas are a kind of transitional phase between deep artificially induced coma and full consciousness,” Zieger explains. “A patient in a waking coma may breathe on their own, and can open their eyes but can’t focus them. They do not react to their surroundings.” Some, he adds, stay in this state for days, weeks, months, even years. Zieger recalls one case where the patient only emerged from a waking coma after 50 years.

“A friendly, trusted atmosphere with family members and positive feelings are, in my experience and in the light of recent research, very important in helping patients out of waking comas,” Zieger says.

Two further problems when patients wake up, says Claudia Spies, are withdrawal symptoms from the narcosis medication, which affect 60% of patients, and delirium that is marked by thought disturbances, memory and concentration problems, as well as character changes and delusions or aggressive behavior.

Delirium affects 50% to 80% of patients who regain consciousness and can result in many complications if they are not dealt with immediately. In cases of delirium, the risk of dying within the next six months is increased threefold.

A lot of patience is required to determine which residual effects will become permanent. It takes several months to establish what damage is irreversible and what the brain can compensate. According to Zieger, that is why “rehabilitation is started very early on,” and even in intensive care much importance is attached to stimulating the patient’s mobility of body and spirit.